Power circuit electrical connection system and method

ABSTRACT

A connector system is provided for use in power applications, such as for conveying three phase power in electrical enclosures. The system comprises plug assemblies in which a power conductor is mounted in a floating arrangement with elastically deformable conductive structures extending from either side thereof. A mating receptacle may be mounted on a bus conductor. Three such arrangements may be provided for conveying three phase power. The structures allow for plug-in mating of the system components while accommodating considerable translational and angular misalignment between the connector parts.

BACKGROUND

The present invention relates generally to the field of electricalconnectors, and more particularly to a plug-in-system capable ofcarrying high voltage and current loads.

A wide range of electrical connection systems have been developed andare currently in use. For applications that simply convey low voltageand current, or data, simple plug systems are available. For highervoltage and current applications, such as in industrial power electronicsystems, sizable conductors are required that need to interface in highefficient manners to convey the desired power between connection points.In industrial contexts, for example, electrical enclosures may bedesigned with power bus bars carrying three-phase power, such as in abackplane of an electrical cabinet. Devices may be connected to the busbars by means of stabs which elastically envelope the bus bars tocomplete the connections. In other contexts, bus bars are designed tointerface by bolted or other connections, with quite sizable connectorsor direct contact between bus bars routing power to and from powerelectronic components, such as motor drives, switchgear, circuitprotective components, and so forth.

Larger and higher powered connections are particularly difficultinsomuch as some flexibility is often desired for removal of componentsfor servicing, while maintaining excellent current carrying capabilityduring normal operation. In certain contexts, conductive wire braids andother flexible structures have been employed for this purpose. In somecontexts, however, hard connections are preferred in which AC power buscomponents are screwed to one another and ultimately to conductors usedto route power to or from power electronic devices and switchgear. Wherecomponents are intended to be removed from time to time, such as forreplacement or servicing, the problems are exacerbated by the need toproperly align the bus bar components, despite slight variations in thelevel or position of the components in the electrical cabinet. Suchmisalignment is often inevitable, and current designs for powerconductors in such environments are unable to accommodate suchmisalignment while maintaining good connections during operation.

There is a need, therefore, for further improvement in electricalconnections designed for high voltage and high current applications.There is a particular need for a design that will allow for somemisalignment between bus components and that allows easy withdrawal ofone conductor from another, particularly in three-phase applications.

BRIEF DESCRIPTION

The invention provides a novel connector system designed to respond tosuch needs. The system is based upon the use of conductive busses orsimilar structures with which a receptacle or plug assembly can beassociated. The receptacle receives the plug assembly and electricalconnections are made between inner conductive surfaces of the receptacleand resilient conductive components associated with a mating conductoror bus. As the connection is made up, then, the resilient elements areelastically deformed to provide the desired electrical connectionbetween the conductor or bus elements.

In accordance with one aspect of the invention, therefore, an electricpower connector system comprises a plug assembly comprising a generallyplanar power conductor and two side conductor assemblies. Each sideconductor assembly is secured to a respective side of the generallyplanar power conductor via a conductive support, and comprises aplurality of inner conductive elements in contact with the powerconductor, and a plurality of conductive extensions opposite theconductive elements. The conductive extensions being biased outwardlyand compressible towards the support. A generally fork-shaped conductivereceptacle has opposed sides that contact and compress the conductiveextensions when the plug assembly is inserted into the receptacle.

The invention also provides an electric power connector system thatcomprises three such plug assemblies, three generally fork-shapedconductive receptacles, and three bus conductors, one of the receptaclesbeing conductively secured to a respective bus conductor to convey threephase power between the bus conductors and the generally planar powerconductors. The arrangement may be configured to convey three phasepower.

The invention also provides a method for making an electric powerconnector system. In the method, a plug assembly is assembled comprisinga generally planar power conductor and two side conductor assemblies,each side conductor assembly being secured to a respective side of thegenerally planar power conductor via a conductive support and comprisinga plurality of inner conductive elements in contact with the powerconductor, and a plurality of conductive extensions opposite theconductive elements, the conductive extensions being biased outwardlyand compressible towards the support. The plug assembly is configured tomate with a generally fork-shaped conductive receptacle having opposedsides, wherein the opposed sides contact and compress the conductiveextensions when the plug assembly is inserted into the receptacle.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of an exemplary three-phase connectionsystem in accordance with certain aspects of the present invention;

FIG. 2 is a perspective view of an exemplary plug assembly for use inthe system of FIG. 1;

FIG. 3 is an exploded view of the exemplary plug assembly of FIG. 2;

FIG. 4 is a perspective view of an alternative configuration of a plugassembly for use in the system;

FIG. 5 is an exploded view of the arrangement of FIG. 4;

FIG. 6 is a top view illustrating the system receptacle and plugassembly prior to mating; and

FIG. 7 is a top view of the same components once mated.

DETAILED DESCRIPTION

Turning to the drawings, FIG. 1 illustrates an exemplary connectorsystem 10 designed for use in high voltage and high currentapplications. By way of example, the system may be suitable for use inpower electronic circuits, switch gear, motor drives, and otherapplications in a variety of voltage and current ranges. The systemillustrated in FIG. 1 is particularly well-suited to use in electricalcabinets wherein three-phase power is routed through bus bars to and/orfrom power electronic components and switchgear. As will be appreciatedby those skilled in the art, in such applications, power from a source,as indicated by reference numeral 12 is typically routed through acabinet, such as in a rear backplane of an electrical enclosure. Powerexiting from the connections is fed to various loads as indicated byreference numeral 14. Such loads may include the circuit protectivecomponents in the cabinet, but also various control components, such asmotor drives, motor starters, contactors, relays, and so forth. Itshould be noted that although the incoming power is illustrated ascorresponding to reference numeral 12 in the outgoing power to the loadis indicated by reference 14 in FIG. 1, the roles of the variouscomponents of the connector system may be reversed in practice.

In the illustrated embodiment, the incoming power 12 is channeled to busbars 16 which will commonly comprise significant conductive elementssuch as bars of copper. The connector system then comprises receptacles18 that are secured to the bus bars and extend from a conductive surfaceof the bus bars. The receptacles include side contacts 20 and 22 and arear side 24 joined to the side contacts. The receptacles are secured tothe bus bars by fasteners 26. The fasteners provide mechanical supportfor the receptacles as well as hold the rear face of the rear side inclose conductive contact with the respective bus bar. Front extremitiesof the side contacts 20 and 22 of the receptacles 18 are provided with achamfer surfaces 28 to facilitate engagement of the receptacles withmating plug assemblies as described below.

Plug assemblies 30 are provided that may be formed as an extension ofmating conductors 32. In some embodiments, the mating conductors mayalso be substantial metal components, such as copper bars which extendto switch gear or other circuitry, such as motor controllers. The plugassemblies 30 are supported on component supports (not shown) and tiedto the mating components that receive power from the bus bars via thereceptacles and plug assemblies. Each plug assembly also includes one ormore supports 34 secured to the mating conductor 32. These supports holdand provide mechanical support for resilient contact structures. Asdescribed more fully below, the resilient contact structures makecontact with the mating conductor 32 and the supports 34, and extendoutwardly from the supports 34 to make contact with the inner surfacesof the side contacts 20 and 22 of the receptacles when the plugassemblies are inserted into the receptacles.

FIG. 2 illustrates an exemplary plug assembly of the type shown in thesystem of FIG. 1. Again, the plug assembly includes a mating conductor32 which carries current during operation. The conductor 32 carries oneor more supports 34 for the resilient contact structures 36. Each ofthese resilient contact structures includes a series of conductiveelements including inner conductive elements 38 and conductiveextensions 40. These conductive elements and conductive extensionscomprise assemblies of supports and flexibly mounted conductors. Theinner conductive elements 38 make contact with the mating conductor 32when the supports 34 are mounted onto the mating conductor. Theconductive extensions 40 comprise conductive material which extendsoutwardly from the supports and that can be elastically deformedrelatively easily by pressure on either side of the structure. In apresently contemplated embodiment, the supports include upper and lowerT-structures forming grooves 46 into which the resilient contactstructures 36 are inserted. The resilient contact structures andsupports are held onto the mating conductor 32 by a series of pins orfasteners 48 that are received in apertures 50 formed in the supportsand corresponding apertures 52 formed in the mating conductor. In apresently contemplated embodiment, the apertures 52 of the matingconductor are somewhat oversized, while the apertures 50 of the supportsprovide a press fit for the fasteners. This arrangement, in conjunctionwith the elastically deformable nature of the inner conductive elements38 allow the mating conductor 32 to “float” between the elasticconductive structures on either side of it. This, and the elasticallydeformable nature of the conductive extensions, allows for considerabletolerance to misalignment when making up the connector system.

The supports 34 are made of a conductive material through which currentpasses during operation. Conductive elements 38 of the resilient contactstructures to extend inwardly to make good contact with the side facesof the mating conductor 32. In the illustrated embodiment the matingconductor is a generally planar conductive metal such that the faces mayprovide good surfaces for contact with the inner conductive elements 38.In operation, a current path is established from the resilientextensions 40, through the supports 34, and through the inner conductorelements 38 to the mating conductor 32.

FIGS. 4 and 5 illustrate a U-shaped support 58 that may be used in placeof the separate supports of the previous embodiment. The U-shapedsupport similarly forms a mechanical support for the resilient contactstructures 36, but may wrap fully around an end of the mating conductor32. As with the previous embodiment, the U-shaped support is made of aconductive material and allows for the inner connective elements 38 ofthe resisting contact structures to contact faces of the matingconductor 32 to maintain it in a “floating” position between extensionsof the U-shaped support. In the illustrated embodiment the U-shapedsupport is secured to the mating conductor 32 by pins or fasteners 48 asin the previous embodiment.

FIG. 6 represents a top view of the foregoing structure (the firstembodiment) prior to mating of the receptacle 18 and the plug assembly30. As shown, the receptacle is supported on the electrical bus, andextends outwardly from the bus with the side contacts 20 and 22presenting a volume into which the plug assembly 30 is introduced. Thereceptacle width 60 is dimensioned to allow for slight elasticcompression, deformation or movement of the conductive extensions 40 asthe plug assembly is pressed into the receptacle. As discussed above,the side contacts may be formed with chamfer surfaces to facilitate suchcompression. The plug assembly is presented with the conductiveextensions in a relaxed state to extend outwardly from the sides of theplug assembly. An outer dimension of the supports 34, indicated byreference numeral 62 is less than the inner width 60 of the receptacle,while a relaxed width 64 of the conductive extensions is somewhatgreater than the inner receptacle width 60. Thus, as the plug assemblyis urged into the receptacle, the conductive extensions will beelastically deformed, compressing somewhat to conform to the inner width60 of the receptacle. This orientation is shown in FIG. 7 wherein theplug assembly has been fully engaged into the mating receptacle.

It should be noted that the use of the conductive extensions 40 andother components of the plug assembly allow for both translational andangular misalignment of the plug assembly with respect to thereceptacle. That is, as illustrated in FIG. 6, if the access of thereceptacle is somewhat displaced from the access of the plug assembly,the two may nevertheless make adequate contact owing to thedeformability of the inner conductive elements 38 and the conductiveextensions 40. Similarly, angular misalignment, as indicated byreference numeral 66 in FIG. 6, may be accommodated by the conductiveelements and extensions. That is, in the case of slight angularmisalignment, the conductive elements and extensions along each side ofthe receptacle may compressed slightly differently, while stillmaintaining adequate contact.

It should be noted that any desired number of conductive elements may beused on each side of the plug assembly, particularly depending upon thepower rating of the connector system. The length of the side contacts 20and 22 are sufficient to allow for full engagement of the plug assemblyin the receptacle so that all conductive extensions are in contact witha conductive surface of the side contacts 20 and 22.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

1. An electric power connector system comprising: a plug assemblycomprising a generally planar power conductor and two side conductorassemblies, each side conductor assembly being secured to a respectiveside of the generally planar power conductor via a conductive supportand comprising a plurality of inner conductive elements in contact withthe power conductor, and a plurality of conductive extensions oppositethe conductive elements, the conductive extensions being biasedoutwardly and compressible towards the support; and a generallyfork-shaped conductive receptacle having opposed sides, wherein theopposed sides contact and compress the conductive extensions when theplug assembly is inserted into the receptacle.
 2. The system of claim 1,wherein the inner conductive elements comprise elastically movableelements that hold the generally planar power conductor in a floatingposition between the two side conductor assemblies.
 3. The system ofclaim 1, wherein the support comprises two separate conductive supports,one conductive support being disposed on each side of the generallyplanar power conductor.
 4. The system of claim 1, wherein the supportcomprises a generally U-shaped support element secured around an end ofthe generally planer power conductor.
 5. The system of claim 1, whereinthe support is secured to the generally planar power conductor viafasteners.
 6. The system of claim 5, wherein the fasteners comprisepins.
 7. The system of claim 6, wherein the generally planar powerconductor comprises apertures through which the pins pass to maintainthe generally planar power conductor in a floating position between thetwo side conductor assemblies.
 8. The system of claim 1, wherein theconductive extensions comprise spring-like conductors that areelastically deformed when the plug assembly is inserted into thereceptacle.
 9. The system of claim 1, wherein the conductive extensionson each side of the generally planar power conductor are configured todeflect to accommodate misalignment between the generally planar powerconductor and the receptacle.
 10. An electric power connector systemcomprising: three plug assemblies each comprising a generally planarpower conductor and two side conductor assemblies, each side conductorassembly being secured to a respective side of the generally planarpower conductor via a conductive support and comprising a plurality ofinner conductive elements in contact with the power conductor, and aplurality of conductive extensions opposite the conductive elements, theconductive extensions being biased outwardly and compressible towardsthe support; three generally fork-shaped conductive receptacles eachhaving opposed sides, wherein the opposed sides contact and compress theconductive extensions when the plug assembly is inserted into thereceptacle; and three bus conductors, one of the receptacles beingconductively secured to a respective bus conductor to convey three phasepower between the bus conductors and the generally planar powerconductors.
 11. The system of claim 1, wherein the support comprises agenerally U-shaped support element secured around an end of thegenerally planer power conductor.
 12. The system of claim 10, comprisingthe inner conductive elements of each side conductor assembly compriseselastically movable elements that hold the generally planar powerconductor in a floating position between the two side conductorassemblies.
 13. The system of claim 10, wherein the support of each plugassembly comprises two separate conductive supports, one conductivesupport being disposed on each side of the generally planar powerconductor.
 14. The system of claim 10, wherein the generally planarconductor of each plug assembly is mounted between respective sideconductor assemblies to hold the generally planar power conductor in afloating position between the two side conductor assemblies.
 15. Amethod for making an electric power connector system, comprising:assembling a plug assembly comprising a generally planar power conductorand two side conductor assemblies, each side conductor assembly beingsecured to a respective side of the generally planar power conductor viaa conductive support and comprising a plurality of inner conductiveelements in contact with the power conductor, and a plurality ofconductive extensions opposite the conductive elements, the conductiveextensions being biased outwardly and compressible towards the support;wherein the plug assembly is configured to mate with a generallyfork-shaped conductive receptacle having opposed sides, wherein theopposed sides contact and compress the conductive extensions when theplug assembly is inserted into the receptacle.
 16. The method of claim15, comprising mounting three generally fork-shaped conductivereceptacles on respective bus conductors, the receptacles being disposedto mate with respective plug assemblies to convey three phase powerbetween the bus conductors and the generally planar power conductors.17. The system of claim 15, wherein the support comprises a generallyU-shaped support element secured around an end of the generally planerpower conductor.
 18. The method of claim 15, comprising the innerconductive elements of each side conductor assembly compriseselastically movable elements that hold the generally planar powerconductor in a floating position between the two side conductorassemblies.
 19. The method of claim 15, wherein the support of the plugassembly comprises two separate conductive supports, one conductivesupport being disposed on each side of the generally planar powerconductor.
 20. The method of claim 15, wherein the generally planarconductor is mounted between respective side conductor assemblies tohold the generally planar power conductor in a floating position betweenthe two side conductor assemblies.